Showing papers on "Microchannel published in 1980"

Current gain parameters of microchannel plates

Abstract: The current gain characteristics of microchannel plates (MCPs) are discussed in light of optimization of the design parameters of MCPs. The paper extends over such topics as optimum channel length-to-diameter ratio, maximum current gain condition, and end-spoiling effect.

Voltage measuring device

Abstract: PURPOSE:To improve an S/N ratio and to enhance voltage measuring accuracy by providing a disk shaped microchannel plate so as to cover a semispherical grids in a device which analyzes the energy of a secondary electron beam emitted from a specimen when an electron beam is irradiated to the specimen, thereby enhancing trapping rate of secondary electrons CONSTITUTION:The specimen 3 is arranged in a grid group 1 comprising semispherical grids G1-G3 The large area microchannel plate 11 is arranged over the grid G3 Said microchannel plate 11 comprises a substrate 11a and an anode part 11b, and is shaped in a disk shape A central hole 11c, through which the electron beam 5 irradiated on the specimen 5 passes, is formed at the center thereof The secondary electrons 5a, which are emitted from the specimen 3 when the electron beam 5 is irradiated on the specimen 3, are collected by the microchannel plate 11, and amplified so as to increase sensitivity Many small holes 11d perforated in the substrate 11a in said microchannel palte 11 The secondary electrons 5a jump into the said holes 11d and reflection is repeated The secondary electrons are emitted from the inner walls of the holes 11d, and multiplication is accomplished

Gain stabilized microchannel plates and MCP treatment method

Abstract: Microchannel plates having increased gain and significantly improved aging characteristics are provided by forming a thin film of a cesium compound on the channel walls. In an exemplary embodiment, a surface film of cesium hydroxide is applied to the interior wall surfaces of an MCP by saturating the plate with a solution of the compound, then allowing the solvent to evaporate. The cesium hydroxide residue on the walls subsequently is converted to cesium oxide by a high temperature bake.

Image Processing Operations Achievable With The Microchannel Spatial Light Modulator

Abstract: The Microchannel Spatial Light Modulator (MSLM) is a versatile, optically-addressed, highly -sensitive device that is well suited for low-light-level, real-time, optical information processing. It consists of a photocathode, a microchannel plate (MCP), a planar acceleration grid, and an electro-optic plate in proximity focus. A framing rate of 20 Hz with full modulation depth, and 100 Hz with 20% modulation depth has been achieved in a vacuum-demountable LiTaO3 device. A halfwave exposure sensitivity of 2.2 nJ/cm2 and an optical information storage time of more than 2 months have been achieved in a similar gridless LiTaO3 device employing a visible photocathode. Image processing operations such as analog and digital thresholding, real-time image hard clipping, contrast reversal, contrast enhancement, image addition and subtraction, and binary level logic operations such as AND, OR, XOR, and NOR can be achieved with this device. This collection of achievable image processing characteristics makes the MSLM potentially useful for a number of smart sensor applications.© (1980) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Microchannel X-ray image intensifiers

Abstract: The construction and working principles of a microchannel and the characteristics of channel plates are briefly described. X-ray image intensifiers can be built by use of this electronic multiplier with an X-photon-electron converter, and a conventional phosphor screen for the output. Three main types are considered: the scintillation image intensifier, the metallic converter image intensifier, and the direct-detection image intensifier. The description and the main characteristics are given for each type of intensifier. Also considered are the main limitations of microchannel image X-ray intensifiers; namely the limitations in diameter and uniformity and, for the whole system, due to the limited number of photons available which limit spatial resolution, the lifetime and the noise factor, which can also be serious drawbacks for particular intensifiers. So, even taking into account that some interesting characteristics of microchannel plates (variable gain, no distortion, fast response) have not been fully exploited, the developments of such intensifiers, in the near future, will be probably limited to some special uses both in medical and industrial fields. Technological improvements and reductions of price can modify, of course, the present situation in a few years.

Mass spectrometer with a multichannel ion detector based on microchannel plates

Abstract: Position sensitive detectors based on microchannel plates were introduced in a mass spectrometer. With the help of this multichannel ion detector, the measurement time and errors are reduced significantly.

A Microchannel Plate Based Detector for a Heavy Ion Beam Spectrometer

Abstract: The design parameters and operating characteristics of the detector used in the Brutus and Fannie heavy ion beam spectrometers at the SuperHILAC facility are described. The detector utilizes a 25 mm diameter microchannel plate array to obtain gains of 102 to 108 with a linear dynamic range of 103. It has had over three years of almost maintenance-free service, detecting ion beams from carbon to xenon with energies between 1.2 and 8.5 MeV per nucleon.